


Kiss Me, Kill Me

by saltnhalo



Category: Supernatural
Genre: Alpha Castiel (Supernatural), Alpha/Beta/Omega Dynamics, Assassin Castiel (Supernatural), Assassin Dean Winchester, BAMF Castiel (Supernatural), BAMF Dean Winchester, Canon-Typical Violence, Guard Dean Winchester, M/M, Murder Husbands, Omega Dean, Scenting, True Mates
Language: English
Status: Completed
Published: 2018-09-17
Updated: 2018-09-17
Packaged: 2019-07-13 08:23:08
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 4,668
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16014059
Author URL: https://archiveofourown.org/users/saltnhalo/pseuds/saltnhalo
Summary: Seasoned hitman Castiel Novak is just looking to take out his target and get paid, but should've accounted for the fact that he may not be the only assassin at tonight's party...Cue the mysterious, green-eyed man who is more of a match for Castiel than anyone he's ever met.





	Kiss Me, Kill Me

**Author's Note:**

  * For [Darmys](https://archiveofourown.org/users/Darmys/gifts).



> I started writing this a while ago for Darmys, and finally got around to finishing it. Thank you to [Adaille](https://archiveofourown.org/users/adaille/pseuds/adaille) for beta-ing, you superstar.
> 
> [Russian translation](https://ficbook.net/readfic/7651744)
> 
> Enjoy <3

Castiel has never liked parties.

They’re often too crowded, for one, even those hosted by the upper-class and social elite. With such big mansions, one would think a three hundred-strong guest list wouldn’t feel quite as overwhelming, but oftentimes it’s just too much of a sensory overload for him. Too many colours, too many scents, too many people to make small talk with, all while trying to focus on just one objective.

He’s always done his best work alone and at a distance, preferably with only his sniper rifle for company, and tonight Castiel wishes that were the case. Unfortunately, however, this particular job requires a little more… finesse. It’s been requested that the hit be done up close and personal, and who is Castiel to deny his employer’s wishes when there’s such a hefty paycheck in it for him?

First, though, he actually has to make the hit. He can’t get ahead of himself.

Another elegant beta in a cocktail dress appears by his side, and Castiel forces down his frustration as he plasters on a smile. He’s not interested in networking or gossiping or whatever inane business happens at these extravagant parties, but for the sake of his cover, he plays along. She’s aesthetically pleasing—well-dressed, draped with expensive jewelry and smelling of floral perfume—but she’s not at all what Castiel would be interested in on _any_ day, let alone enough to distract him while he’s in the middle of a job.

After a few minutes of flirting, the woman seems to lose interest—his scent blockers make him hard to read, and he’s not exactly encouraging her with his body language. Castiel isn’t sad to see her go. He’s also not keen on being dragged into conversation again, since he has a job to do tonight, so he makes his way over to one of the many tables of hors d’oeuvres and takes his time picking over the offerings.

From here, he’s able to observe most of the party—and more importantly, his target.

Martin Glousetsky is a rich, old alpha who owns the expensive mansion, enjoys throwing lavish parties such as this one, and has made many enemies in his long and extravagant life. Castiel twists the ring on his right hand once around his ring finger, but doesn’t touch the button hidden beneath the small gemstone that will open the hollow space built into the inside of the ring.

From here, Castiel can see Glousetsky where he’s chatting with his guests, smiling and laughing in a way that certainly looks genuine to the untrained eye. Castiel knows better, having read the dossier on his dealings with politicians, police and the mafia alike. Nice man or not, though, it doesn’t matter. Castiel is here to do a job, and the job isn’t over until Glousetsky’s heart has stopped beating.

Whether or not he deserves what is about to happen to him is none of Castiel’s concern.

Castiel checks his watch, then finishes his tartlet with one neat bite. The food is exquisite, and that’s one good thing about being down here on the ground instead of up in an adjacent building with a sandwich and an apple, but the hors d’oeuvres aren’t quite enough to compensate. The sooner he finishes this job, the sooner he can get out of here.

Glousetsky lifts his flute of champagne and then brings it to his lips, the crystal flashing in the light of the many ornate chandeliers above. Castiel rolls out his neck. It’s nearly 10pm, and it’s time for him to put his plan into action.

He’s moving before his target even snaps his fingers for another drink, already an organic part of the crowd when the waiter Glousetsky called places a full flute on his tray and begins weaving his way through the partygoers.

He flexes his fingers, counts his paces, and stumbles right into the young omega. The guy is obviously well-trained, but Castiel’s bump was designed to put him off balance, and the tray wobbles precariously on his hand. Castiel catches it just in time, fingers delicately wrapped around the top of the fine crystal glass. “I’m so sorry,” he says earnestly, as he helps the man right himself and his tray.

The waiter assures him that it’s fine, it happens all the time, and continues on his route to a now impatient Glousetsky. Castiel surreptitiously snaps his ring shut and goes to wash his hands.

The poison doesn’t take long to take effect, and not even five minutes later, Castiel begins to notice his target’s swaying, the paleness to his face, the fine tremor to his hands. His words begin to slur, and the group of men and women he’s talking to can’t hide their concern. It’s only once Glousetsky collapses onto the ground, the shattering of glass and sound of screaming punctuating his fall, that Castiel decides he’s seen enough. If he risks staying any longer, there’s a possibility that he could be caught, and the likelihood of Glousetsky surviving that poison is nonexistent.

As the ballroom erupts into panic and shouting, Castiel quietly takes his leave, unseen.

But perhaps he’s not quite as invisible as he’d thought.

He makes it halfway down the hallway towards the side entrance he’d picked out for his escape when a voice calls after him: “Hey! Stop right there!”

 _Shit_. Castiel freezes in his tracks. He’s letting his guard down, it seems. He really should’ve checked for any extra guards as he was making his way through the mansion—it had been stupid to assume that they’d all be preoccupied with Glousetsky. Perhaps it’s time for him to consider retiring, if he’s going to start making stupid mistake like this.

Slowly, he turns around.

There’s a man at the end of the corridor, holding a gun in both hands. He’s tall, freckled, and with the distance and the dim lighting, Castiel can just make out the glint of green eyes and the wary expression. He’s dressed in the crisp white shirt and black suit of Glousetsky’s guards, and nothing about this situation bodes well for Castiel at all.

All he can do right now is try to play it off. “Is there a problem?” he asks, pitching his voice so that it carries to the man, but keeping it as non-threatening as he can. “I don’t think the gun is really necessary, I was just looking for the bathroom.”  
  
The guard steps closer—and now that he’s better lit, Castiel can see that he’s quite handsome. He has the facial features of a classical omega, but the body structure and height of an alpha. For Castiel, who doesn’t really care what gender or designation his partners are, it’s quite the enthralling combination, but this really isn’t the time to be thinking about that. Not when he’s staring down the barrel of a pistol.

“You haven’t been in the ballroom?” the guard asks suspiciously, but even though it doesn’t sound like he completely trusts Castiel’s story, he makes the mistake of lowering his gun just a fraction.

Castiel takes that as his opportunity, and lunges to the side, bursting shoulder-first through the nearest door to his right. The man shouts something as Castiel slams the door closed behind himself. He has just a handful of seconds before the guard follows him, and his brain works double-time to figure out a plan.

It seems as though he’s found himself in some sort of gym and swimming pool combination. The air is warm and humid, and the still waters of the pool glisten in the light of the moon that filters in through the floor-to-ceiling windows on the far side of the huge room. Over there is all open space, though, and it’s no good for what Castiel needs. Instead, he ducks behind a rack of weights, makes himself as small as possible, and waits with his eyes trained on the door.

In the silence of the cavernous room, it’s not hard for Castiel to pick out the sound of running footsteps in the hallway outside. They slide to a stop right outside the door, and then they pause. Smart man, not just rushing in right away. Still, it’s not like it’ll help him.

Although, Castiel must admit that he does want to try to avoid killing this one. He’s only here for Glousetsky, after all, and he prefers not to create extra casualties. Plus, killing such a handsome man would be a waste—although Castiel may have blown his chance now, if the guard suspects him for what he is.

Slowly, the door opens, a wedge of light from the hallway spilling into the room. The guard’s pistol appears first, then his arm, his shoulder, and the rest of him. Castiel holds his breath as the door swings shut.

“Are you in here?” the guard calls into the room. His voice echoes off the glass and the water and bounces away into silence. His earpiece hangs loose against his collarbone. “I just want to talk to you. It’s about what you saw in the ballroom.”

His movements are sharp and precise, and Castiel is impressed. For all that he may have faltered in the hallway, being unsure of who Castiel was, it definitely looks like he knows what he’s doing now. He sweeps the room with his pistol, and from here, Castiel can see his green eyes tracking every possible movement, every flicker of a shadow or creak of the building settling.

His training, however good it may be, won’t be enough. No mere guard can match up to a trained assassin.

Castiel slips out of his hiding spot on silent feet and creeps up behind the guard. By the time he is noticed, he’s almost upon the man, and it’s too late. In one swift move, Castiel disarms him, steps in close, and uses the man’s bodyweight to put him flat on his back on the marble floor.

All the breath leaves the man’s lungs at once, and he groans. Before he can react, Castiel is straddling his chest, one hand splayed across his throat and the other holding the gun in front of the guard’s face. His lashes flutter, and he focuses first on the barrel of the gun, and then looks past it at Castiel.

“I shoulda been more careful, huh?” he rasps. Castiel’s hold on his throat loosens slightly, and then the man clears his throat. His fingers curl, then uncurl, on the ground beside his head. “Gonna keep pointing my gun at me?”

“I don’t believe I have another choice right now. You were following me.”

“Yeah, because you ran away. Kinda suspicious behaviour, if you ask me.”  
  
The man is still just looking up at him, lips parted, no signs of fear on his face or his flat, blocked scent. Beneath Castiel’s palm, the pulse in his throat is steady. This man is surprisingly calm considering he’s staring down the barrel of a pistol.

Castiel squints down at him, and the man raises his eyebrows. “Are you the one who killed Glousetsky?” he asks, his voice even and steady. He doesn’t even blink.

Like Castiel is going to admit that to one of the man’s own guards. And why should he give the guard anything? It’s not like Castiel is the one pinned to the ground right now—this man isn’t really in the position to be asking questions.

He tilts his head slightly, and then those perfect lips curl up into a grin. It’s not at all the reaction he was expecting, and he wishes the guard wasn’t wearing blockers so that he could know exactly what’s going on in his head.

“I thought that might’ve been the case,” the guard says, and he winks. “Guess I should thank you for doing my job for me.”

_What?_

All at once, the man explodes into action. His hands come up to grab Castiel’s wrist, forcing the gun away and twisting until he has no choice but to let go. The gun clatters to the floor and skitters away, and the man twists in Castiel’s hold. Before Castiel has the chance to put his full body weight on the man, he slips out from underneath the alpha with a grunt and rolls fluidly to his feet—no mean feat in a suit like that.

Stunned and caught on the back foot, Castiel scrambles to his feet. The gun lies several feet away from them, no closer to one than the other. They stand facing each other, both tense and _ready_ , neither breaking eye contact.

The man is still grinning. “Looks like you let your guard down a little there, huh? You probably should’ve scoped the party out a little better.”

Yes, yes he should have. _Idiot_. Glousetsky is a man with many enemies, and he should have suspected that he wouldn’t be the only person sent to end the man’s life. He bares his teeth. “You were here to kill Glousetsky too? Who are you?”

The moonlight plays over the man’s freckled skin and the pearlescent white of his teeth. “Yeah, I was here to kill him. I was playing the long game, though. Much more fun.” He winks at Castiel. “Name’s Dean. You?”

 _Dean_. Castiel bites back the growl forming in the back of his throat. “Castiel. And that’s a shame, since I got there first. You should’ve picked your opportunities better—it’s not like the idiot checked what was going into his drinks.”

The man— _Dean_ —chuckles. “Cas-ti-el, huh? I wasn’t shitty enough to give you my fake assassin name, but whatever.” Castiel grinds his teeth, but Dean continues, smirking. “Man, you poisoned him? So boring. I was waiting for a much more dramatic opportunity. But whatever floats your boat, I guess.”

Personally, Castiel had been more interested in getting the job done than aiming for any kind of dramatic flair. “That’s a shame for you, but it doesn’t look like there’s any point in taking this further. I took him out, did you a favour, and now we can both go home.”

He’s not looking for any kind of fight. He did his job, Glousetsky is dead, and now he just wants to go home without all this extra hassle.

Unfortunately, it doesn’t look like that’s going to be the case. Across from him, Dean sighs and spreads his hands.

“I wish it was that simple. Unfortunately, you didn’t really do me a favour. If my employer finds out that I’m not the one who killed Glousetsky…” His lips twist wryly. “I’m not gonna get paid. But if only one assassin walks out of here tonight…”

There’s no need for him to finish the sentence. Castiel knows exactly what he means.

He could always try reasoning with the man, promising to split the money with him, but… he also doesn’t take kindly to being pushed around or threatened. There’s a reason he’s lived this long doing what he does, after all. He’s been in the business from a young age, and there’s not much that can phase him at this point, not even facing off with another assassin. A growl rumbles deep in his chest. “You want to kill me? I’d like to see you try.”

There’s a moment of stillness, moonlight washing out the space between them. Castiel watches Dean’s chest rise and fall, notes the miniscule flex of his fingers—and then the man shifts his weight, faster than Castiel could have expected, and lunges.

Castiel is more than ready, though. He blocks the punch, sidesteps the kick, and uses the opportunity to elbow Dean squarely in the chest before dancing away.

Dean grunts, but otherwise doesn’t react. In fact, he _grins_ , a flash of white teeth in the silvered moonlight. “Gonna have to do better than that, hotshot,” he teases, raising his fists and squaring up. Despite the aggressive stance, though, he stays light on his toes, and Castiel doesn’t doubt that if he were to throw a punch right now, he’d hit nothing more than empty air.

This guy is  _good_.

He flexes his fingers and exhales, steadying himself. There’s no point in responding to the jab—Dean wants to rile him up, so he’ll make a mistake, and Castiel isn’t that stupid. He takes a calculating step forward, Dean’s eyes following his every move, a definite wariness beneath the teasing and cockiness.

Dean shifts his balance, and Castiel takes that slight distraction as an opportunity to strike. Dean sidesteps the punch to his stomach and blocks the strike to his head effortlessly, but Castiel counters the responding flurry of blows just as easily.

Punch, strike, block, duck, kick, spin, strike.

It’s like a choreographed dance, the way the two of them can each interpret the other’s moves so easily, and even almost predict their next attack. They move together, a whirling mass of deadly strength and precision that would easily have felled a lesser opponent by now. But Dean is no ordinary opponent.

He finds himself wanting to keep fighting Dean hand to hand like this—the gun is close by, and he could probably best Dean if they were to grapple for it, but there’s something enthralling about this dance. He’s never felt anything like this with anyone, and he wants, _so badly_ , to beat Dean. To pin him back against the marble and relish the victory of triumph.

Castiel is breathing hard now, sweat beading at his temples. Dean looks the same, though—when they separate for a fraction of a second, they both gulp in a lungful of air, and then throw themselves straight back into the fray. Dean jabs at Castiel’s jaw, Castiel steps out of the way and blocks the attack, then retaliates with a kick that Dean neatly deflects. They’re _so_ evenly matched.

Until Castiel lets Dean slip in under his defenses, and only just manages to block a vicious flurry of blows. He catches Dean’s wrist on the last roundhouse punch, just inches from his head, and suddenly they’re face to face, chest to chest. 

Dean’s breath hitches, and his eyes go wide. His teeth bite down gently on his bottom lip, and when he looks up at the alpha through his lashes, Castiel’s brain screeches to a halt. _Omega?_ his biological brain asks, even though there’s no way for him to tell, even though this man fights better than any alpha Castiel has ever come up against.

Omega or not, there’s no denying that he’s absolutely _beautiful_. Castiel can hardly breathe.

And then the gentle lip-bite gives way to a wicked smirk, and there’s no time for Castiel to react before Dean strikes him in the jaw and kicks him directly in the centre of his chest with enough force to send him staggering backwards.

As he tries to regain his balance, Castiel’s shoe slips on the wet marble where the water just barely laps over the side of the pool. The last thing he sees before his head cracks against the pool’s edge is Dean’s green eyes, and then everything goes black. There’s a disorienting feeling of sliding, falling, sinking.

His head radiates with sickening, nauseating pain, the cold swamps him, sinking into his bones. His eyes sting when he tries to force them open, and his limbs won’t obey him.

When Castiel tries to breathe in a lungful of air, he chokes.

He’s drowning.

His head feels like it’s been split open, and he can’t figure out which way is up as he tries to expel the water in his lungs. It only makes things worse, and he understands what it feels like now. He understands what it feels like to die, to face that impending fate as fear and panic and _cold_ overtake his mind.

He moves his limbs weakly, grasps at nothing in the hope that he’ll find the water’s edge, his fingertips meeting only empty water. There’s no way to tell how long he’s been drowning—it could be seconds, it could be minutes. It feels like forever.

This wasn’t how he wanted to go.

And then a hand closes around his collar and _pulls_ , and all of a sudden Castiel is splayed across warm marble.

He hacks and heaves, expelling everything he can from his lungs until he’s just coughing weakly against the floor. When he opens his eyes, blinking them blearily, there are three pairs of feet that swim dizzyingly in his vision. Someone saved him.

With weak, trembling movements, Castiel tries to push himself up off the floor. His arms shake, but he persists—he won’t lie here on the ground like a half-dead thing.

A hand fists in his hair and pulls, tugging on his aching scalp and sending a bolt of pain through Castiel’s head. He groans as he’s roughly pulled upright, onto his knees, where he teeters on the edge of collapsing again. His wet hair drips into his eyes, and his soaked suit feels achingly heavy on his exhausted, weak limbs.

Dean’s face swims sickeningly in and out of his vision.

“Gotta say, I was expecting you to have some better skills than that, hotshot. I mean, falling for the pretty face and then getting knocked out by a _pool_? That’s a little sad, dude.” His chuckle resonates through Castiel’s head, and makes him want to throw up. He tries to focus on the man’s face, and slowly it condenses down into one image instead of three.

“I should’ve let you drown in there, but I figured I’d give you a little more dignity than that. Besides, a guest drowned in a pool looks suspicious, but a guest shot by a guard? I can just say that you’re the one who killed Glousetsky—which, after all, is the truth. They think I caught the culprit, my boss thinks I framed some poor schmuck, everyone’s happy.”

He pulls Castiel’s head back further, and the cold barrel of the pistol caresses Castiel’s jaw. Something flickers behind green eyes. “Everyone except you, I guess,” he whispers, then winks. “Sorry about that.”

Dean twists Castiel hair between his fingers and presses the barrel of his gun against Castiel’s forehead. The alpha meets Dean’s cool gaze, lets out a shuddering breath, then closes his eyes. There’s no way he can fight back, not when his whole body feels like lead and even the smallest movement creates a pain so intense that he wants to vomit.

He accepts his fate, bares his neck in submission, and waits for the bullet.

It doesn’t come.

The silence stretches out for what feels like eternity, until finally, Castiel slits his eyes open.

The barrel of the gun has dropped, and Dean is staring at him with wide eyes and an open mouth. In the silvered moonlight, Castiel swears that he can make out the faintest flecks of gold in Dean’s eyes—he _is_ an omega.

“You…” Dean whispers, and his voice cracks. His grip in Castiel’s hair loosens, and the gun slowly lowers further. “Is that… you?”

This must be a product of the throbbing pain resonating out from the back of Castiel’s skull. He’s imagining the shock on Dean’s face, the gold filaments in his irises, the tremble of the hand holding the gun. “Is what me?” he rasps, his throat hoarse from the pool water. He doesn’t understand, doesn’t understand why Dean hasn’t killed him yet, why he’s asking these questions.

Dean inhales, and the tremble of his hand grows more pronounced. “The scent,” he says, his voice shaking. “That scent. Is that you?”

It takes a second for Castiel to understand what he means. The pool water has washed off his blockers, and while he now reeks of chlorine, his rain and pine scent is beginning to come through in subtle undertones. Still, it’s nothing special. He struggles to focus his gaze, and squints up at Dean. “Yes?”

Dean sinks to his knees, and his fingers drag through Castiel’s wet hair. The pistol clatters to the ground.

 _What is happening?_ They’re face to face now—there are definitely threads of gold in Dean’s eyes, and Castiel aches to know what he’s thinking. His expression is one of shock, but _why_ , when he was so ready to end Castiel’s life?

“Of course it happens to me like this,” Dean whispers, and he scrubs a hand over his face. When it drops away, the omega is grinning—wide and overwhelmed. “Jesus. And I almost… Thank god you fell into the pool, or I never would have known.” His giddy laugh is thick with relief.

“Dean, you… what is going on?” Now that he’s no longer facing certain death, Castiel is starting to regain his wits. His head still throbs, but he tries to shove the pain into the background for now.

Dean’s eyes widen. He lifts the collar of his shirt to his nose, then laughs again and drops it. “God, you don’t know, do you? Hold on.”

He scrubs at his neck for a few seconds, and Castiel’s rational thought spins away as his gaze is drawn down to the smooth skin of Dean’s throat. He’s beautiful, and deadly, and unclaimed, and…

Oh.

 _Oh_.

It’s unlike anything Castiel has ever smelled before. He sways closer, his eyes half-lidded, lips parted to draw the scent in over his tongue. When he falls too far, Dean catches him with steadying hands on his shoulders, and Castiel blinks up into gold-threaded green. “ _Oh_ ,” he says simply. Because he understands now. He knows what Dean had known as soon as the water had washed away Castiel’s blockers.

“Yeah.” Dean’s voice is soft, and his fingers curl into the fabric of Castiel’s wet suit jacket.

Dean. Assassin, rival, killer.

 _Mate_.

“Thank you for not killing me,” he says wryly, tiredly.

Dean chuckles. “Yeah, it’s probably not great to kill your truemate, is it?”

Because that’s what they are. Truemates. And the more Castiel looks at Dean, tastes the scent of rum and cherries on the air, feels the weight of his gaze and of his hands… The more he wants to get to know this omega.

“No,” he agrees, and his lips curl up into a smile. “But I’m sure you could start making up for it by taking me out to dinner.”

~~ 

Unsurprisingly, they don’t make it to dinner.

They end up back at Dean’s place. He treats Castiel’s head injury, then makes pasta in a pair of sweatpants while Castiel showers off the chlorine. When Castiel comes back out, dressed in an old pair of Dean’s pajamas and smelling wholly and unquestionably like himself…

Well. They can reheat the pasta for lunch tomorrow.

Dean shifts against Castiel, his back pressing against the alpha’s chest. In the faint glow of the moonlight, his skin is pale, freckles like silver stars across his shoulders and the line of his cheekbone as he turns his head.

“I can’t believe I thought you’d given me a fake name,” he mumbles, and amusement dances through his scent. Castiel presses his nose against Dean’s neck and breathes it in—will he ever tire of scenting his truemate?

“Incredibly disrespectful,” he agrees, his words quiet against the curve of Dean’s throat. Still bare, still untouched, but one day, Castiel will put his mark there, just as he will relish Dean laying claim to his own skin. “I’m sure I can think of ways you can repay me, though.”

Dean laughs. “I’m sure you can too. For now, though, get some sleep. I’ll wake you up in a couple hours in case you’re concussed.”

Castiel hums against Dean’s neck and nods—sleep sounds fantastic, especially now that he’s curled up in bed with his truemate, who smells like sex and Castiel and everything that he’d never known he’d wanted. 

He falls asleep with Dean’s scent in his nose and Dean’s skin against his and the feeling that finally, at long last, something that had been missing has fallen perfectly into place.

**Author's Note:**

> If you enjoyed this, please leave a kudos or a comment!
> 
> Find me on tumblr [here](http://saltnhalo.tumblr.com), and subscribe to me on ao3 [here](https://archiveofourown.org/users/saltnhalo) <3


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